# insMotionPose

Model for 3-D motion estimation

## Description

The insMotionPose object models 3-D motion assuming constant angular velocity and constant linear acceleration. Passing an insMotionPose object to an insEKF object enables the estimation of 3-D motion, including orientation, angular velocity, position, linear velocity, and linear acceleration. For details on the motion model, see Algorithms.

## Creation

### Description

example

model = insMotionPose creates an insMotionPose object. Passing model to an insEKF object enables the estimation of:

• The orientation quaternion from the navigation frame to the body frame.

• The angular velocity of the platform, expressed in the body frame.

• The position of the platform, expressed in the navigation frame.

• The velocity of the platform, expressed in the navigation frame.

• The acceleration of the platform, expressed in the navigation frame.

## Examples

collapse all

Create an insMotionPose object and pass it to an insEKF object.

motionModel = insMotionPose
motionModel =
insMotionPose with no properties.

filter = insEKF(motionModel)
filter =
insEKF with properties:

State: [16x1 double]
StateCovariance: [16x16 double]
MotionModel: [1x1 insMotionPose]
Sensors: {}
SensorNames: {1x0 cell}
ReferenceFrame: 'NED'

Show the state maintained in the filter.

stateinfo(filter)
ans = struct with fields:
Orientation: [1 2 3 4]
AngularVelocity: [5 6 7]
Position: [8 9 10]
Velocity: [11 12 13]
Acceleration: [14 15 16]

## Algorithms

The insMotionPose object models the orientation-only motion of platforms. The state equation of the motion model is:

$\begin{array}{l}\stackrel{˙}{q}=\frac{1}{2}\omega q\\ \stackrel{˙}{\omega }=0\\ \stackrel{˙}{p}=v\\ \stackrel{˙}{v}=a\\ \stackrel{˙}{a}=0\end{array}$

where:

• q = (q0, q1, q2, q3) is the quaternion from the navigation frame to the body frame.

• ω is the angular velocity of the platform, expressed in the body frame.

• p is the position of the platform, expressed in the navigation frame.

• v is the linear velocity of the platform, expressed in the navigation frame.

• a is the linear acceleration of the platform, expressed in the navigation frame.

## Version History

Introduced in R2022a